desert

Introduction

desert, arid region, usually partly covered by sand, having scanty vegetation or sometimes almost none, and capable of supporting only a limited and specially adapted animal population. The so-called cold deserts, caused by extreme cold and often covered with perpetual snow or ice, are quite distinct from the deserts of warm regions; cold deserts cover about one sixth of the world's surface. It is estimated that warm deserts form about one fifth of the land surface of the world.